Arnaud's Blog

Opinions on open source, standards, and other things

The cost of wifi and wifi security

I break a long silence to write about something I just found out about wifi and wifi security. Admittedly it may not be an earthshaking discovery but having searched for info on the subject it doesn’t seem like it is covered much so it seems worth a blog post (plus, for once, I can give this higher priority than everything else.)

There is a lot of info out there on how to set up your home wifi and set it up to be secured. However, little is said about what this will cost you. I mean in loss of speed.

I did some tests over the weekend and here is what I found, using, with a cable internet connection:

Directly connected to the cable modem (no router, no wifi): ~23Mbps download

Connected via cable through my router (“Belkin Wireless G Plus Router”), no wifi: ~17Mbps download. Gasp, that’s a 25% loss right there. I’m no network expert so I don’t know if that’s normal but I sure didn’t expect to lose that much just going through the router. But that’s actually nothing. Read on.

Connected via wifi through my router, with an open connection, no security: ~14Mbps download. Ouch. Here goes another 18%. Unfortunately that’s not even close to be the end of it.

Connected via wifi through my router, with security set to WPA-PSK TKIP: ~8Mbps download. Wow! That’s yet another 42% loss just for turning the security on, which every website out there says you MUST do.

The loss due to the security setting motivated me to run tests against the various security options my router supports. It turns out that all WPA options and WEP 128bits basically lead to the same poor results.

Setting security to WEP 64bits is the only security option that doesn’t severely impact performance: ~13Mbps.

Sad state of affair!

WEP is known to be very weak and easy to break in minutes by a knowledgeable hacker. 64bits is that much faster to break than 128bits obviously.

So here you have it. The choice is between fast and unsecured or secured and slow. Stuck between a rock and a hard place.

Obviously results will vary depending on the router you use but, here is the rub: when shopping for routers I find very little/no info on the impact of turning security on. Most products claims are typically in optimal circumstances, as in “up to xxx”. and relative, as in “10x faster than xxx). This is of no help determining what performance you will actually get.

One thing that plays a role in the performance you get is the CPU your router is equipped with. Yet, from what I’ve seen, this is not a piece of information that is readily available.

To make matters worse, from what I’ve seen, websites such as CNET don’t highlight that aspect either. So, you’re pretty much on your own to figure it out.

Beware. Run some tests and see for yourself what you get.


November 28, 2010 - Posted by | standards | , , , ,


  1. The secure+fast version remains the ethernet cable though.
    No one should use unsecured wifi (WEP is unsecured), and I think 8Mbs is a reasonable speed for most uses.

    I think that’s why people usually don’t insist on speed loss, but still insist on the importance of securing the connection.


    Comment by Nico | November 29, 2010 | Reply

    • Yes, I think that’s right. But 8Mbps isn’t fast enough to watch streaming HD videos.

      This is what made me start looking into this problem. The video gets interrupted every now and then while the player buffers more data.

      So for a media center you still need to use a cable.

      Comment by Arnaud Le Hors | November 29, 2010 | Reply

  2. You’re right, I did not think of this usage which requires greater speed, still this is probably an everyday use for many people.

    Comment by Nico | November 29, 2010 | Reply

  3. I’ll add that, in many countries, unsecured wifi also = leaving yourself open to liability for copyright infringement by other people..


    Comment by Brenda | November 29, 2010 | Reply

    • Indeed.

      Comment by Arnaud Le Hors | November 29, 2010 | Reply

  4. […] cost of wifi and wifi security (continued) Just to clarify my post on the cost of wifi and wifi security, I’m not advising anyone to turn security off just because it may significantly be slowing […]

    Pingback by The cost of wifi and wifi security (continued) « Arnaud’s Open blog | November 29, 2010 | Reply

  5. Yes, I noticed I have not said it yet: this post proposes a very nice benchmark that will be useful in many situations!
    Thanks a lot for doing it and writing about it.

    Comment by Nico | November 30, 2010 | Reply

  6. Yes, I knew that there is always some bandwidth loss if you use router but the figures you mentioned in this article really shocked me. Now I will try it myself. By the way thanks for sharing the information.

    Comment by Belkin router support | December 29, 2010 | Reply

  7. You raised some good points for a novice like me. I really wondered why all this happens and I will always go for good speed + good security.

    Comment by John | November 16, 2011 | Reply

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